[lucky american]

I want to also suggest seeds and soap or the ability to make soap.
You can buy seeds and keep them in the fridge or a cool, dark, dry space. These will keep for years as I have seeds from the 90’s still viable.
Lettuce can be grown all year . It may be a bit leggy.
Soap will be a commodity. People will want to keep clean.

[Tammy8]

I have had good luck saving seeds in canning jars in a cool dark place, I have limited fridge space but have used seeds from many years ago stored in canning jars with success.